Zero-Footprint Optical Metrology Wafer

Using a heterogeneous integration approach, we have encapsulated prefabricated monolithic components, a photodiode and LED, inside a silicon wafer form factor to achieve a self-contained, environmentally sealed system. We have demonstrated the utility of the metrology wafer for data mapping and process monitoring in hostile environments such as plasma, CMP, and chemical etching.

Our work now focuses on the design and implementation of a thin film stack to achieve spectroscopy capability in a form factor that will fit inside of the metrology wafer.

Once completed, proof-of-concept experiments will be carried out to show that the spectroscopy implementation can be used to monitor chemical concentrations via the fluorescence phenomenon. We hope to show that this could monitor the photoacid compound in photoresist applications for the semiconductor industry.